Factors influencing anode concentration overpotentials in SOEC

The charge transfer and mass transfer mechanisms in solid oxide electrolysis cells (SOEC) were modeled including the effect of the three-phase boundary length on the anode concentration overpotential. The numerical results agree well with experimental data. The effects of the anode porosity, the pore radius and the diffusion layer thickness were analyzed. Further parametric analyses showed the effects of an oxygen partial pressure on the anode concentration overpotential. The results show that increased anode porosity and pore radius both reduce the concentration overpotential. However, the increase diffusion layer thickness increased the concentration overpotential. The oxygen partial pressure can be increased to reduce the anode overpotential. The model can be used to analyze anode designs and adjust the operation conditions to improve anode performance.